Don't rely on inferior I/O in gdb.base/restore.exp

There seems to be no point in relying on stdio here.  Simply use
gdb_continue_to_end instead.

(not removing the printf calls, as the .c file is half generated.)

gdb/testsuite/ChangeLog:
2015-07-29  Pedro Alves  <palves@redhat.com>

	* gdb.base/restore.exp (restore_tests): Use gdb_continue_to_end.

gdb/testsuite/ChangeLog

@@ -1,3 +1,7 @@
+2015-07-29  Pedro Alves  <palves@redhat.com>
+
+	* gdb.base/restore.exp (restore_tests): Use gdb_continue_to_end.
+
 2015-07-29  Pedro Alves  <palves@redhat.com>
 
 	* gdb.base/call-signal-resume.exp: Remove check for

gdb/testsuite/gdb.base/restore.exp

@@ -79,20 +79,7 @@ proc restore_tests { } {
         }
     }
 
-    if ![gdb_skip_stdio_test "run to completion"] {
-	send_gdb "continue\n"
-
-	gdb_expect {
-	    -re "exiting" {
-		pass "run to completion"
-	    }
-	    timeout { 
-		fail "(timeout) run to completion"
-	    }
-	}
-    } else {
-	gdb_test "continue" ".*" ""
-    }
+    gdb_continue_to_end "" continue 1
 }
 
 set prev_timeout $timeout